I'm planning to put solar panels on my roof and since they're going to be up there for a good 15-20 years I think it would be a good idea to paint it beforehand since it would be hard to repair the roof once the solar panels mounted.
The roof in question is an unpainted Galvanized Long Run type. It's in overall fairly good condition, but there are a few small areas that are starting to show a little bit of spot rust.
I think that I need some sort of cold galvanizing paint and have so far looked at the following.
1. Resene Galvo One. $102 / 4L (currently on sale)
2. Dulux Cold Galv. $198 / 4L
Looking at the MSDS sheet for the Galvo One, there doesn't appear to be much zinc in it. I'm guessing the active ingredients are the Barium metaborate (which may have Zinc Oxide in it) or the Alkyd Resin resene.com.au/archspec/msds/Galvo_One.pdf
The Dulux Cold Galv on the other hand appears to be 60% Zinc dust which looks to me to be a whole lot better msds.duluxgroup.com/pdf/shess-en-cds-020-000000010790.pdf
Both are described as primers.
Basically I just want to treat the roof so it doesn't corrode. It's going to have solar panels across the entire roof, so I don't care what it looks like underneath.
Which would work best for me? Also, does it really need a topcoat on top of the 'primer' ?
Any comments of help with this much appreciated.
Felix